Question

Given f(x)=3(x-1)(x-7) what is the minimum output value of the function

Answer 1

-27

Explanation:

f(x) = 3(x-1)(x-7)

= (3x-3)(x-7)

= 3x^2 - 24x + 21

when f(x) = 0, x = 7 or 1

x-intercept of vertix of the graph = (7+1 )/ 2 = 4

f(x) attains it's minimum when x = 4

The minimum output value = 3(4-1)(4-7) = -27